The present invention relates generally to a Jacquard loom, and more particularly, toward a Jacquard loom having hooks extending vertically between upper and lower rakes, the hooks being lifted by parallel sets of knives along a non-linear path so as to reduce friction between the hooks and rakes.
In German Pat. No. 2,344,363, there is described a double lift, open shed Jacquard loom having a lower set of lifting knives that laterally shifts during both upward and downward movement, and an upper set of knives that moves vertically along a straight line. Alternatively, the upper and lower sets of knives are alternately laterally shiftable during upward and downward movement. These measures prevent the descending hooks with unsupported hook noses from unintentionally coming into engagement with an assigned knife of a rising set of knives.
In the area between the upper and lower hook rakes, transverse forces are exerted on the hooks which lead to flexing of the hooks in that area. As a consequence strong tension and frictional forces arise, and the standard downward pull of the hooks by weights or springs does not sufficiently hold the hooks on the lower set of lifting knives. Furthermore, as a result of friction, the energy required for moving the hooks is substantial, and a great amount of wear can be caused within a short time.